diff --git a/readme.txt b/readme.txt
index b90ececf5..752703c1d 100644
--- a/readme.txt
+++ b/readme.txt
@@ -73,6 +73,8 @@
 *****************************************************************************
 
 *** 2.3.3 ***
+- FIX: Some ARMCMx makefiles refer the file rules.mk in the ARM7 port (bug
+  3411180)(backported to 2.2.8).
 - FIX: Fixed wrong check on CH_DBG_ENABLE_STACK_CHECK setting (bug 3387671)
   (backported to 2.2.7).
 - FIX: Fixed wrong APB1 frequency check (bug 3361039)(backported to 2.2.7).